I remember, a loooong time ago, an old boss of mine told me that sometimes people cross your path and you may not immediately understand why, but later on, down the road, you'll figure it out (and maybe appreciate it more! [or less]) I applied that logic to almost every person I've ever dated/friends with and realized it only counts towards those people still in my life.
I often wonder, though, what about The Potentials? Those people that have always sparked your curiousity, but never did anything about?
Take into consideration a dude I will call Mr. T( not because of the resemblance to the great actor, but because his last name is really friggin' long), I had a one night stand with the cutie ohhhhhh maybe 4 years ago (and, yes, it was fantastic). But along came ex-gf and fucked it allll up. My huge ego and innate sense of self-respect prevented me from continuing the budding romance and I took the moral high road of BTFU (Backing The Fuck Up) and denying any and all sexual involvement. I do, however, wish whatever was/could have happened was given a chance.
Then there's Mr. Bomb.com himself. The Ex That Will Never Go Away. I still want to get naked from time to time. I still wish I could have had more patience. But that's the love that never was. I still think he's hot.
And finally, Mr. R. He's married now to a woman he finds sub par. I had a few one nighters with him, as well (screaming included), and he just never left my memory. Nor I in his, either, apparently. He still wants me [around] and has told me multiple times. I do not condone sex with married people. I think its wrong in so many ways. Its not my friggin' fault you're unhappily married. But in his words,"You just up and left without a word. And it was time." Sorry, dear sir, the best I can do is buy you a beer.